Harvard’s Walter Willett,
M.D., MPH, Dr.P.H., who launched the second Nurses’ Health Study in 1989, echoes that sentiment. “We started mostly with a focus on cancer and heart
disease, but now we’re looking at virtually every major condition, including psychological effects, kidney stones  you name
it.”

For example, the study has found that a diet high in sugar-sweetened and diet soft drinks, refined grains and processed meat can raise the
risk of developing type 2 diabetes; and that obesity and weight gain increase the risk of kidney stone formation.

Emily Beauregard sees the potential
for a psychological study based on a trend she’s noticed while enrolling people into the Southern Community Cohort Study at the Family Health
Center’s Portland Clinic in Louisville, Ky.

“Most of our patients’ (annual) household income is less than $15,000,” she says.
Many “have been diagnosed with depression ... Education, housing, emotional health—everything plays into your well-being.”